roadrunner wrote:I am not certain there are definitive and/or comprehensive answers here. There are such things as transient pulmonary nodules, and they can grow or shrink and disappear on their own. I’m also not sure that growth (or reduction) was ever definitively established or well-quantified in some/all of these, at least from what you posted. (The one that showed 4mm growth may be an exception. I don’t think you said if it, or one of the smaller ones, is the “stable” one now.) The differences you mention—for example, 1mm growth (and you don’t give all the growth/reduction values, so it’s hard to judge)—are very small, and in micro-nodules at that. I believe 1mm “growth” would be generally regarded as “stable” in a person without known cancer. (If I remember right, 2mm is the threshold in that context.) Things are different where there is a history of cancer, but this still tells you something.
There are many vagaries when it comes to pulmonary nodules of this size. For example, inter-observer variability is +\- 1.72mm I believe (one study). Also the “slices” used for the CT, respiration at the moment of scan, contrast/no contrast (a significant factor), even electronic caliper factors and software variability can have effects (significant in this size range) that mimic growth or reduction in size. The challenge is that most of the nodules in this case are really small, so the relative impact of those factors may be increased. I wonder if the oncologist was “hedging” this when Xeloda was chosen for that reason. (Though you would presumably have been told that.) I must admit that I’m not sure what the PET results mean in this context, but the oncologist didn’t seem to regard that as definitive either.
All of this may explain (or be behind) the most recent radiologist’s impression, but the situation seems uncertain and potentially complex. Figuring that out would require (at least) a deep dive with your father’s team, and possibly a discussion with a (the?) radiologist. I’d certainly be interested in whether there is another potential etiology, e.g., an infection or prior smoking, especially if such a candidate fell into the period when these first definitively appeared. (You do say they “may” have appeared on prior scans, but the meaning of that is unclear.)
From reading your posts, it’s definitely possible that one or more of these are metastases, but I don’t think that’s certain. Your father’s oncologist thought it was concerning enough to do something, but they chose not to operate (even on the 1cm nodule (which you say would’ve been “easy,” and would likely have yielded enough material to test)). It may be that the treatment was just a conservative approach to observation.
That’s my reaction to your questions, anyway. Hope it helps in some way. But the bottomline appears to be that things are going in a good direction, which is awesome!
Thanks a lot for such a comprehensive response, I’ll add some direct information from the last ct report to give more information about the size reduction:
Image 14 of series 4 left upper lung nodule measures 7mm, prior study 6mm (**the last PET scan 3 months ago had this one at 7 so oncologist says this is a stable reading)
Image 28 there is a 3mm nodule right lower lung, prior study 5mm
On image 43 right medial lower lung nodule measures 5mm, previous study 10mm
On image 44, 2mm nodule right lower lung on prior study 5mm
So as you can see it was the largest nodule that grew the most from 6 to 10mm (that sounded the alarm for recurrence last time) that shrunk significantly on this last scan. The interval growth on the other nodules were all 1 or 2mm, but I assume this finding across all nodules was further suggestive of malignancy for the oncologist. The biopsy on that larger nodule wasn’t performed previously because I assume the interval growth was convincing enough for the oncologist to be certain that it was malignant. Even given that, the findings of that ct simply said “interval growth of nodules” and made no suggestion of metastasis or recurrence.
My dad was never a smoker and I can’t really think of any infectious history, although he does get pretty bad seasonal allergies. CEA isn’t a good marker for him and was always low throughout his initial treatment. The PET SUV uptake as you can see are all well below numbers suggesting malignancy, but the literature i’ve read says that these readings aren’t really useful for nodules that small.
I guess the conservative, attentive approach that his oncologist is using is akin to a ‘better safe than sorry’ attitude, even if there are some inconsistencies as you have pointed out. Regardless, I am grateful that whatever is going on is controlled at the moment.